Oswald enters, wearing a light overcoat and smoking a pipe. Pastor Manders is pleasantly shocked at how closely he resembles his famously upstanding father. Mrs. Alving glows with pride at the maturity her son shows in dealing with the Pastor's muddled apologies for having formerly disapproved of his way of life. The Pastor describes the way the outlines of Oswald's mouth resemble the late Captain Alving's, but Mrs. Alving insists that Oswald does not favor his father in the least. She asks him not to smoke in the garden room, and Oswald complies, saying that he was only smoking because it was his father's pipe; he had smoked it only once before, as a small child, at his father's urging, and remembers having been sick. Mrs. Alving insists that this must have been a dream.
The conversation turns to Oswald's life abroad. The Pastor emphasizes the importance of the ancestral home and of living with a family. Oswald mentions that he has lived with families, albeit not families officially married by the church. The Pastor is appalled, but Mrs. Alving supports her son. Oswald becomes emotional in his arguments, complaining about the hypocrisy of many Norwegian men who declaim the bohemian lifestyles he loves.
When Oswald enters, he is wearing a light overcoat. This contrasts with the Pastor's entrance; the Pastor was wearing a heavy overcoat and carrying an umbrella, heavily shielding himself from the dark weather. These details are highly symbolic: while Oswald, as we will see later in the play, is practically driven crazy by the gloom—both literal and symbolic—of the community and its natural setting, the Pastor is well adjusted to it. This is also reflected in Oswald's speech. It is impassioned; he speaks in bursts of adjectives, whereas the Pastor's speech is ponderous, highly rhetorical, and full of stock phrases. The Pastor lives his life according to a concrete set of ideals, whereas Oswald acts from the heart.
Mrs. Alving reacts oddly to the Pastor's belief that Oswald resembles his father. She doesn't like the idea at all. As we will learn by the end of the first act, this is because she very much dislikes her former husband but idealizes her son and imagines that she has saved him from his father. Yet despite her internal rejection of her former husband's ways, Mrs. Alving is careful to preserve his public reputation. Thus, she rejects as untrue the anecdote her son tells about his father forcing him to smoke: she doesn't want either of the men to know of her late husband's weaknesses.
In Oswald and the Pastor's argument over marriage, we see further exposition of their differing worldviews. Oswald declares that Norwegians who condemn Italian artists living together unmarried are hypocrites because they themselves are not free from their own forms of corruption. Little does he know that his father was prone to such moral decay. Later in the play, Oswald will complain about the lack of sun in Norway, compared to sunny Italy where he has been living. Clearly, Oswald takes issue with more than the lack of natural light in his hometown—he takes issue with the prevailing lack of intellectual and moral enlightenment.